One type of ink-jet printer includes a carriage that is reciprocated back and forth across a sheet of paper that is advanced through the printer. The reciprocating carriage holds a pen very close to the paper. The pen is controlled by the printer for selectively ejecting ink drops from the pen while the pen is reciprocated or scanned across the paper, thereby to produce characters or an image on the paper.
The pen carries a reservoir for holding a limited amount of ink. A relatively larger supply of ink is provided in a stationary container that is mounted to the printer. A tube is connected between the supply container and the pen. The tube conducts the flow of ink from the supply container to the pen for replenishing the pen reservoir as needed. Alternatively, the pen and supply container can be constructed so that the pen occasionally engages the supply container to draw ink from the container and thereby replenish the reservoir.
Use of a separate, stationary ink supply is advantageous for a number of reasons. For example, an empty supply container can be replaced with a filled container without also replacing the relatively costly pen.
Unless properly designed, ink supply containers can present problems in handling once they are emptied and removed from the printer. In this regard, the emptied bags may be difficult to compact for handling efficiently. Moreover, residual amounts of ink in the otherwise empty containers may be "pumped" out of an empty container if that container is permitted to expand and contract during handling. It is also important that emptied containers be easily recyclable.